In a blender, mix the first 10 ingredients until well blended. Pour the spiced buttermilk into a gallon sized freezer bag, add chicken thighs into the bag. Push as much air as possible and seal the bag. Refrigerate overnight.

In a gallon sized freezer bag, add flour, garlic powder, chile powder, cayenne, salt and pepper. Close the bag and shake to combine. Take the chicken thighs out of the buttermilk marinade, pat dry chicken with paper towel. Transfer the chicken, one at the time, to the flour bag, and shake to coat. Shake off the excess flour and let sit on the wire rack to dry for about 1 hour.

Add oil into the frying skillet. Heat the oil over medium heat (should reach the temperature of 320 to 340 degrees F). The amount of oil should be enough to completely submerge the chicken while frying. Add chicken into the hot oil, frying them for about 15 minutes or until the center is done and the outside turns golden brown. Remove the chicken from the oil and drain on paper towel. Serve hot.